2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
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<strong>Bolsa</strong> <strong>Chica</strong> Lowlands Restoration <strong>Monitoring</strong><br />
<strong>2008</strong> <strong>Annual</strong> <strong>Report</strong><br />
As a result of the shoal-associated muting and its controlling influence on the functioning of the MTBs<br />
and Freeman Creek, along with other variables (shoal volume and area of low intertidal habitat lost),<br />
maintenance dredging was warranted in <strong>2008</strong> and first scheduled to occur in the fall of <strong>2008</strong>.<br />
In the “Statements of Interest for the Environmental and Beach Profile <strong>Monitoring</strong> of the <strong>Bolsa</strong> <strong>Chica</strong><br />
Lowlands Restoration Project”, a dredging trigger was proposed as follows: “a tidal muting of the<br />
average low tide elevations (Mean Low Water) on the order of 0.5 feet would indicate that the flood<br />
shoal maintenance dredging was warranted”. This should be revised since the Mean Low Water in the<br />
FTB is unlikely to ever be muted prior to failing of the required MTB and Freeman Creek drain-out<br />
conditions. The spring low tide would be a more appropriate parameter to gauge the muting in the<br />
FTB.<br />
While water quality conditions and habitat function within the FTB remained high during all periods of<br />
2007 and <strong>2008</strong>, the operational restrictions within the west MTB and increasing base water levels in<br />
the MTB affect vegetation condition and distribution, as well as tidal circulation. Both of these have<br />
the potential to significantly affect habitat functions. As a result, an appropriate maintenance dredging<br />
trigger related to impacts to tidal drainage from the MTBs should be included to optimize overall<br />
system functioning. This is addressed in Section 3.<br />
2.3. BEACH MONITORING<br />
Introduction<br />
The objective of the beach monitoring program is to develop a quantitative understanding of changes<br />
in the condition of the beaches adjacent to the newly constructed Full Tidal Basin (FTB) entrance<br />
channel. The study area includes portions of the <strong>Bolsa</strong> <strong>Chica</strong> and Huntington Cliffs shorelines. The<br />
monitoring program, which commenced in January 2007, is comprised of semi-annual beach profile<br />
surveys and monthly beach width measurements at seven sites located along a 5.3 km section of<br />
coastline between <strong>Bolsa</strong> <strong>Chica</strong> State Beach and 17 th Street in Huntington Beach. Coastal Frontiers<br />
Corporation conducted the beach profile surveys, while Moffatt and Nichol performed the beach width<br />
measurements. The historical research and collected data analysis was conducted by Coastal Frontiers<br />
Corporation.<br />
Figure 2-8 shows the locations of the beach profile transects used in the monitoring program. Two of<br />
these were established specifically for the monitoring program and were first surveyed in January<br />
2007. Five of the transects had been established previously and were included in the Coast of<br />
California Storm and Tidal Waves Study for the Orange County Region (CCSTWS-OC) conducted by<br />
the U.S. Army Corps of Engineers (USACE 2002).<br />
Transect establishment/recovery activities were conducted prior to the commencement of the initial<br />
beach profile survey. The initial beach profile survey for the <strong>Bolsa</strong> <strong>Chica</strong> Lowlands Restoration<br />
Project was conducted in January 2007. Additional surveys have been performed during each of the<br />
subsequent May and October time periods in 2007 and <strong>2008</strong> (Appendix 1-A). The monthly beach<br />
width measurements commenced in January 2007. The monitoring activities were detailed previously<br />
by Coastal Frontiers (2007a, 2007b, <strong>2008</strong>a, <strong>2008</strong>b, 2009) and are discussed under the methodology<br />
section below.<br />
Merkel & Associates, Inc. 114